


Handcuffs (on you, mama)

by sorteparaplyer



Series: Weight Gain [6]
Category: The Umbrella Academy (TV)
Genre: Aged-Up Number Five | The Boy, Alpha/Beta/Omega Dynamics, Belly Kink, Breeding, Chubby Diego Hargreeves, Conditioning, Daddy Kink, Dirty Talk, Dubious Consent, Fat Diego Hargreeves, Feeding Kink, Humiliation, M/M, Male Lactation, Mpreg, Pregnancy Kink, Sibling Incest, Weight Gain
Language: English
Status: In-Progress
Published: 2020-05-04
Updated: 2020-05-04
Packaged: 2021-03-01 22:40:11
Rating: Explicit
Warnings: No Archive Warnings Apply
Chapters: 1
Words: 3,434
Publisher: archiveofourown.org
Story URL: https://archiveofourown.org/works/23994640
Author URL: https://archiveofourown.org/users/sorteparaplyer/pseuds/sorteparaplyer
Summary: Five's got his omega right where he wants him
Relationships: Number Five | The Boy/Diego Hargreeves
Series: Weight Gain [6]
Series URL: https://archiveofourown.org/series/1450702
Comments: 17
Kudos: 136





	Handcuffs (on you, mama)

**Author's Note:**

> I got an amazing request to do some Five/Diego mpreg + weight gain, and this is what I came up with. Exploring this dynamic was new to me, so I hope I did the request justice! This one goes out to the two people who are going to be interested in this lol

“I won you,” Five whispers in his ear. “Don’t forget that, Diego. I won you and then I ruined you.”

He knows Diego won’t forget. His brother might forget what he was like before—how strong and toned his body was, the easy confidence he stalked around with—but he’ll never forget who he belongs to now.

Five has made sure of that.

“I won’t forget,” Diego says, shaking his head. “I’m yours, Five. All yours.”

“Yes, you are.” Five smiles and presses a kiss to his forehead. Diego’s not the brightest of his brothers—God, he might even be stupider than Klaus—but he was easy enough to train. Five knew that deep down they both wanted the same thing. It just took a little persuading for Diego to allow himself to give in to it.

Now four years on, everything is exactly how Five wants it.

He doesn’t usually like to think of himself as sentimental, but he does love Diego. He loves the look of ecstasy on Diego’s face when he’s being fucked relentlessly into the mattress. He loves how genuinely happy Diego is every time he finds out he’s pregnant again. Diego is dumb and he needs a lot of guidance, even by omegan standards, but Five can’t help loving him anyways. It’s a natural result of the time they’ve spent together and the work Five has put into him.

He sits down on the bed beside Diego, pulls up the hem of Diego’s shirt to expose the massive ball of his belly. His stomach is impossibly round, swollen with Five’s pups and fat from years of baby weight. “Look at you,” Five murmurs, as he runs a hand over the swell of Diego's stomach. “So big for me. And only getting bigger.”

Five’s not sure how many he’s carrying this time—Grace told them at Diego’s last ultrasound, but Five’s already forgotten. He doesn’t care about the pups as much as he cares about stretching Diego’s belly out, breeding him up, making him fatter. Keeping him pregnant so he can’t do anything but lie in bed, vulnerable to Five’s whims.

Diego is the one who cares about their children. Five knows it would be almost impossible for an omega not to. But Diego isn’t really capable of raising them himself. He can nurse them, he’s plenty equipped to do that, but by the time they’re walking he’s inevitably too pregnant to toddle after them. And then he’s too busy nursing newborns, and then he’s swelling with the next brood.

Of course, now that Diego’s put on so much weight, Five isn’t sure it’s really the pregnancies holding him back anymore. The thought makes Five’s cock twitch, compels him to slide his hand between Diego’s thick thighs to the fat mound of his pussy. 

Diego’s response is automatic. He lets out a needy whine as he cants his legs, instinctively offering himself to Five. 

Five bears down with his fingers and smirks when he feels Diego’s underwear dampen with slick. “Desperate for me as always,” he observes coolly.

“Please,” Diego says. 

“Why don’t we get some food into you first and then I’ll fuck you.”

Five can see that Diego doesn’t even think about it, he just nods his head obediently. They both know it’s better that way, with Diego doing as little thinking for himself as possible. Or maybe Diego is just that desperate for food. After all, Five went to a lot of trouble to develop his appetite. 

“You sit tight,” he says needlessly. “I’ll see what’s in the kitchen.”

“Thank you, Daddy,” Five hears, as he leans into a crackle of blue light.

“You’re getting fat, Diego.”

Diego freezes in his tracks and whips around on Five. There’s a carton of ice cream clutched in his hands, along with a big spoon. “ _Excuse_ me?” he spits.

Five crosses his arms in a casual way, keeping his gaze level. “You heard me. I can tell just by looking at your ass that you’ve gained at least fifteen, probably twenty pounds recently.” The corner of his mouth quirks up. “And that’s to say nothing of your gut.”

Diego’s face burns scarlet. There’s a guilty pinch to his expression, like he’s afraid Five knows about the midnight binges in front of the fridge, the skipped workouts in favor of lazier activities. The little dance he’s been doing to try to get into his pants. Of course Five knows about it. The cameras in the house are still functioning, even if he’s the only one who reviews the footage. Then Diego tosses his head in a careless way, as if he can convince Five he really feels so nonchalant about it, and flashes him a cheeky grin. “So you’ve been looking at my ass, huh?”

“Hard not to, when it’s straining those pants like that.”

Diego’s face falls. He sets aside the ice cream and spoon. “Five—”

Five softens a little, reminds himself that this is Diego, and Diego sometimes needs things spelled out for him. “What I meant is, I’ve noticed you getting heavier.” He puts one hand up in a gesture to wait. “And I’m only mentioning it because I think the weight is very becoming on you.”

Diego blinks. “You got a hell of a way of giving compliments, Five, you know that?”

“Sorry,” Five says, almost meaning it. He comes closer, letting his gaze sweep down over Diego’s frame and back up to his face. There’s a bit of pudge clinging to Diego’s cheeks and below his chin, making him look softer, more like an omega should. 

It occurs to Five that Diego might not have changed his habits consciously. Dumb as he is, he might not even realize what he's doing. If that’s the case, Five decides, the fact that he’s finally following his instincts is a good sign.

Diego’s eyeing him like he still doesn’t know what to make of their conversation. He licks his lips. “You really think I look good?”

Five nods, once. “I always thought it was stupid of you to go and get buff like Luther. Like it would change anything about your designation.”

“Hey,” Diego says, bristling. “I never wanted to change my designation. You can be a ripped omega. No one says you can’t.”

“It didn’t get you any suitors, did it?” Five watches as Diego wilts. He can only assume it would be discouraging for an omega, attracting all the wrong kinds of attention while his womb is left unused. After a while Diego must have felt the lacking, even if it was only on a subconscious level.

“Got me plenty of cock though,” Diego grins, making a rather obscene blowjob gesture.

Five rolls his eyes. “God, you’re an idiot. It’s like you can’t even pretend there’s more to you than those slutty lips.” He lets out a sigh. “You know, you can only fight against your biology for so long. Sooner or later the state you’re meant to be in is going to win out.”

“What the hell does that mean?”

Five takes a step towards him. “You have to let go of your pride, Diego. Embrace your nature.” 

Diego snorts. “Okay, sure. And what’s my nature?”

“You want to be fucked,” Five says. He’s pretty sure Diego at least knows that much already. “But not just down your throat,” he continues, coming closer. “I think you want to be filled with a huge cock, pumped full of seed, impregnated, _bred_. And you’re finally tired of waiting to be noticed by an alpha who wants to breed a jock.” He takes another step forward. “That’s why you’re trying to ruin this dumb, jacked body of yours by eating everything in sight.”

Diego’s mouth draws tight for a moment before he stretches it into a smirk. “You got all that from me getting a little chunky? Christ, Five, when’d you have time to become a psychologist?”

Five breathes out through his nose. This conversation isn’t going how he pictured. Though maybe it was a miscalculation on his part to think it would be so easy to cow his stubborn brother. “Maybe I’m wrong then,” he shrugs. “Maybe you don’t really want someone to get you pregnant. Maybe you’re content sucking dick and you don’t even want to know what it’s like to be knotted and filled and fucked within an inch of your life.”

Diego doesn’t answer right away. Five waits for him to turn angry, to tell Five to fuck off and stop projecting his depraved alpha fantasies onto him. But it looks like Diego’s just mulling things over, thinking through what Five said. Five has to remind himself that Diego is still processing the fact that alphas don’t actually want to fuck an omega gym rat. Then, “no,” Diego says softly. “I-I do.”

“You what?”

“I want—all those things.”

Five smiles. “Good. That’s progress,” he says wryly. “Now, do you know where you’re going to get it?”

Diego shakes his head.

“I’ve got some ideas.” Five saunters closer.

“What, _you_?”

“Why not?”

“I mean, it’s not that you’re not handsome, but—”

“Just because I’m smaller than you doesn’t mean I can’t show you a firm hand.”

“I know—”

“And I’m not small everywhere, in case you were wondering.”

“Oh, yeah?”

Five is practically on top of him now, crowding him back against the wall. They’re matched pretty evenly in height, though Five is much slighter than Diego. It would take nothing for Diego to shove him away, sidestep Five and this entire situation all in one motion. But Diego doesn’t move.

Diego lets himself be pushed back, and then he lets Five take his hand and press it over his groin. Five’s only half-hard, but it’s enough to prove his point. Diego’s face goes slack with surprise. He doesn’t resist as Five turns him and presses him to the wall.

Five comes into their bedroom carrying a steaming mug. “I brought you some tea in case your stomach hurts,” he says. “Not that I’ve ever been able to get you to drink tea before, but…”

Diego smiles faintly, pushing himself up in bed. “Did you actually walk all the way up the stairs just to bring me tea?”

“Do you _think_ it’s a good idea to jump through space with hot water?”

“I guess not.” Diego takes the mug, sniffs it, and sets it aside. “My stomach feels fine though. I can eat way more than you think.”

“Oh.” Five swallows thickly. “I’ll get you more food then.”

Diego makes a sour face. “No, that’s okay. Not right now.”

Five knows he could insist, push Diego to eat until he’s truly at his limit and then push him even further just to prove a point. But he decides to let it go for now. He can’t discount the fact that he’s already accomplished so much with Diego. And there’s a certain thrill in knowing there’s still more to be done. “How are you doing?” he asks instead. “Do you still like being pregnant now that you’re officially on bedrest?”

Diego shrugs a shoulder, suddenly sullen. “I’m alright. I don’t like not being able to move around.”

“I know it's hard, sweetheart.” Five’s voice is gentle, carefully soothing. They’ve come so far from the days of messy knotting, when Diego would snap at him just as readily as he’d beg for Five’s cock. He knows that someday, once he’s got Diego exactly where he wants him, all these little bumps in the road will be a distant memory. “It’s for the best,” Five tells him. “You were having such a hard time carrying around this belly.”

Diego smiles at that, rubbing a hand proudly over his pregnant stomach. “Feel like I’m about to pop.”

“Unsurprising, considering you’re almost due.”

“Once I have these babies I’m gonna be able to do so many things again. I can get back into boxing, start hitting the gym again.” A sheepish look comes over his face. “Maybe try to slim down a little.”

“Don’t be stupid!” Five snaps, taken aback by the idea of Diego in the gym again. “Didn’t I teach you that’s no life for an omega?” He takes a deep, steadying breath. “Besides, I’m going to have you pregnant again right away. You’re better off just letting yourself get fatter.”

Diego frowns, looking up at Five. For a second it seems like he might argue, but then he looks away and sighs. “Yeah, I guess you’re right.”

Five nods, forces himself to relax. “Anyways, if you think you need a little exercise…” It’s a cheap segue and Five knows it, but Diego immediately perks up.

“I swear, the worst thing about laying in this bed all day is feeling like I’m just waiting around to get fucked,” he grouses. He’s already scooting down to the end of the bed, where Five will be able to fuck him without bearing down on his belly. “I would _love_ your cock right now, Five.”

“Ah ah,” Five tuts. He moves to stand between Diego’s outspread knees, runs his palms over Diego’s plush thighs. “That’s not how you talk to me, is it?”

Diego huffs. “Would love your cock, _Daddy_.”

“Better,” Five says. “I’m gonna fuck you so hard, Diego.”

“God, please.”

Five unbuttons his pants and begins to stroke himself, looking down at Diego. “Remember when we first started fucking, when I’d leave you raw and gaping and you’d beg me to go easy on you?” In spite of himself, Five smiles fondly at the memory. Then he feels his smile sharpening, turning into something that must look predatory and possessive. “All that moaning and crying you did, and yet you never once shoved me off of you.” 

There’s a flash of emotion on Diego’s face, an expression that Five thinks must be shame. Or maybe regret, for the energy he wasted on such half-hearted resistance. “You’re bigger than me,” Five continues. “Probably still stronger than me, even like this. But in the end you always let me do whatever I want to you. Because deep down you always want it, don’t you?”

Color rises on Diego’s cheeks. It takes him a second to realize the question isn’t rhetorical, and then he nods pathetically.

“Answer me.”

“I-I want it, Daddy. Need your cock in me. Always.”

Five grins down at him. “I know you do. And now I’ve got you bred up so good, don’t I? How does it feel to be pregnant by your little brother?”

“It feels good, Daddy." A whimper. "So good.”

“Don’t know why I bother asking when I can just look between your legs and see how wet this is making you.”

Diego’s hips buck up and he whines in frustration. “Five…”

“Shh. I won't make you wait any longer. Get on your side for a second.”

Diego obeys wordlessly, putting a hand to his belly as he shifts onto his hip. Five slides a pillow behind him, then rolls Diego back onto it. Diego cants his knees up, and Five pulls his legs around him.

Five pauses to take in the sight of his brother laid out on the bed, swollen with his pups and already soaking the pillow beneath him with slick. Then, "your tits are leaking,” Five notices suddenly. “Did they just start doing that?”

“I-I don’t know,” Diego stammers. He cups his chest self-consciously, his blush deepening. “I didn’t realize.”

“Don’t be embarrassed, sweetheart. I like seeing what a mess I’ve made of you.” He waits a beat for Diego’s snappy remark, but Diego just nods miserably, accepting what Five has reduced him to. “Okay,” Five says, pushing down a sudden swell of affection. “You’re ready for me now, aren’t you?”

Diego nods eagerly. “Just fuck me, please.”

“I know how much you want it,” Five soothes, as he lines himself up with Diego’s entrance. Then he pushes roughly into Diego, earning a sharp gasp. “I’m going to fuck you so good. All you have to do is let go and give in to it.”

Diego screws his eyes shut and nods, allows himself to be rocked with the rhythm of Five’s thrusts. He loves it, Five can tell. Maybe he even realizes how much he needs it. And yet on some level Five senses that he’s still holding back. Which means they're going to have to keep doing this until Diego fully gets over himself. Luckily, Five’s willing to make that effort. He pulls back and sinks into Diego again, relishing his yelp.

“I’m gonna keep you pregnant,” Five says, quickening his pace. “Keep you home where no other alpha can get to you.” He feels Diego’s hair-trigger body already spasming helplessly through an orgasm. “Gonna fatten you up so our sons grow big and strong on your milk.” 

Diego comes again, gasping pitifully, and Five groans as Diego’s muscles clench around his cock. His own orgasm is building, disrupting his rhythm, turning his thrusts frantic and sharp. “Nobody else is allowed to touch you, fuck you,” Five grits out. “Only me, because I know exactly what you need. I’m the only one who knows how to take care of you, Diego.”

“I know, Daddy,” Diego says. “I know.”

“You’re mine. Say it.”

“Yours. Need you.”

“For what?”

“To take care of me. To b-breed me.”

“That’s right. Too stupid to even get an alpha. Remember? And now you have everything because you have—fuck.” Five’s hips stutter as his orgasm overtakes him. “Now you have me.”

“Thank you, Daddy,” Diego says dutifully. 

“You’re welcome,” Five says, panting. He lets himself slump onto Diego’s belly. “My fat little broodmare.”

Five slides into bed beside Diego, pressing himself snugly against his back. He pulls the blankets up around them to make sure Diego stays warm. “Do you want any more to eat?” he asks.

“Still really full,” Diego murmurs.

“Okay,” Five says easily. Over the years he’s come to recognize the ways Diego says no without saying no. And Diego rarely says no to food. Five reaches over and pats the swell of his stomach. “Hmm. You do feel pretty packed. I’ll put some cocoa butter on your belly tonight after your bath.”

Diego nods and heaves a yawn. “Could fall asleep right now.”

“Go ahead and sleep if you’re tired,” Five says. “You’ve been fed and fucked; you might as well get some rest.” Five isn’t opposed to a nap himself, still feeling loose-limbed and lazy in the afterglow. “You have some time before Grace brings the boys in.”

Diego nods again, snuggling deeper into the blankets. “I’m sure the babies are ready to nurse.”

“Well, you’re nice and full for them.”

“That’s good,” Diego says seriously. “Feel like I leak half of it while you fuck me.”

Five snorts a laugh. “You practically do. That’s why I give you so much to eat—to make sure you’re producing enough milk.”

“Oh, I thought you just liked making me fatter.”

Five smiles, squeezes a thick roll of fat at Diego’s side. “That too, obviously. There are lots of advantages to feeding you like I do.” He slides his hand down to palm the curve of Diego’s ass. “One of them being this fat ass of yours.” His hand moves back up to Diego’s waist—“and these big love handles”—then over Diego’s ribcage, around to his chest—“and of course your tits full of milk.” Five presses a kiss to the back of Diego’s neck. “So _many_ advantages.”

Diego just hums happily and stifles another yawn. 

There’s quiet as Five slowly kisses his way down the slope of Diego’s shoulder. Then, “everything I’ve done with you has been for a good reason,” Five says. “Ever since the first day I fucked you.”

Diego’s eyelids flutter open. “I know.”

“You’re the perfect broodmare now. Fat, milky, and docile.”

Diego lets out a little huff. “I’m not _docile_.”

“Yes, you are,” Five says. “I ruined you, remember? And you let me. You liked it.” He mouths over Diego’s shoulder blade, bites down into the fat of his back. “You _still_ like it.”

“Oh… yeah, I guess so,” Diego says, distantly, as if he can’t quite remember how they got here. Then he laughs. “I used to want to look like Luther.”

“You were stupid and misguided,” Five says sympathetically. “But now I’ve got you exactly how I want you.”

“Docile?”

Five nods. “And so big you couldn’t fight me off even if you wanted to.”

“Why would I want to?” 

Five kisses the indent of his teeth in Diego’s skin. “You wouldn’t.”


End file.
